Measured drawings, commonly referred to as “as-builts”, are a set of architectural line drawings that are made from measurements of existing structures or building sites. These drawings accurately delineate the subject buildings and sites in their current existing condition. Typically used to display information for structural and aesthetic evaluation they are the first documents required in the remodel construction permit process. Thus, a measured drawing is always created after a building or structure is completed, sometimes many weeks, months, or years later. Measured drawings can include a floor plan, site plan, section and elevation drawings as well as structural engineering drawings that illustrate foundation and roof framing details to name a few. As they are defined, measured drawings contrast with architectural construction documents commonly referred to as “blueprints” which are created before the building or structure is built.
Measured drawings are used by a variety of people for a wide range of tasks. They are used for rentable space calculations, real property legal records, facilities management databases, historic structure records and emergency access plans among others. For example, an obvious user is an architectural or construction firm that wishes to ensure a particular building or site was constructed according to the architectural blueprint or design plans. Civil engineers, factory and plant designers, and landscape designers use measured drawings for similar purposes. Other, less obvious users of measured drawings include building and office managers, who may for example wish to determine and track the layout of offices within a particular floor of a building; and facilities managers, who will typically use measured drawings as a precursor to adequately coordinate the installation of facilities (electrical, plumbing, air-conditioning, etc.) after a new building has been completed structurally. Measured drawings are also of great use to the legal and insurance industry for gathering an accurate assay of a building's structural composition; and to emergency (fire, police, rescue) departments for creating accurate maps of major buildings that may at some point be entered or searched. In an increasingly important field, measured drawings are also used prior to renovation of older and perhaps architecturally significant buildings to verify the current state of the building or job-site.
A great advantage of measured drawings over the more ubiquitous and commonly known “blueprint” style of drawing is that a measured drawing takes into account and reflects any changes made to the building or structure subsequent to the initial construction period. Blueprints are almost never updated to reflect minor structural changes, such as moving doorways or windows, and are rarely updated to reflect even major changes, such as wall and ceiling modifications, and “add-ons”. For some buildings, such as an old or domestic residence, a blueprint may never have existed, and if one does exist it is likely to be out of date and unuseable. Additionally, measured drawings can include features such as cabinets, fittings, fixtures and furniture, that may never have been specified in a blueprint or original floor plan.
The traditional process of gathering data for these unique drawings has not changed, employing limited technology and no standard methodology. The practitioner, usually an engineer or architect, must rely on his or her own logic. The typical solution has been a two person team of operators, armed with a camera, tape measure, pencil and sketchpad, who visits the job-site (a building, plant, engineering project or work area). The team takes a variety of measurements at each location (in each room of a building for example), and sketches a diagram with annotations for every line on the paper. The structural data, in the form of these photos, notes and sketches is then taken back to the office for transcribing into measured drawings, with either pencil and straight edge, or with the aid of a computer aided drawing (CAD) application.
Clearly, the traditional process is lacking in a standard methodology in which data is collected and verified. There are no set rules as to whether a sketch should be created for every structural element prior to leaving the work site, and there are no fixed links between the data measured and the sketch drawn-both are somewhat subjectively generated and dependent on the skill of the measurer/drawer respectively. The accuracy of the final measured drawing is dependent on a number of factors:                First, the skill of the operator in taking the initial measurements, and the accuracy of his/her instruments may effect the accuracy of the data. Skilled operators will obviously take better measurements than un-skilled operators, but sometimes even operators of equal skill have to make judgment calls as to how to proceed, and at that point their determinations may differ. Since the traditional process affords no rigorous schema or guidelines for taking measurements, discrepancies may creep in when two or more operators are working on the same job-site (as is a common occurrence). Furthermore, using traditional methods, measurements are most often manually taken (for example with a measuring tape), and then manually recorded (on paper). Very little automatic measuring/recording is ever used.        Second, there is no link between taking measurements and linking the measurements of one structural feature or one object to another. The operator takes a set of measurements and records them on paper (such as for example, wall 1: length, 12 feet; height, 8 feet). The next entry maybe for another wall (wall 2: length, 8 feet; height, 8 feet), but no attempt is made to link or relate the two walls (entries) to one another. Typically, the only link that exists between two such entries is that the surveyor or operator personally knows them to be, say, at a right angle to each other, or has taken the foresight to sketch the walls appropriately. Such subjectiveness in linking structural components (walls, windows, and other objects such as doors and furniture) means that most often only the operator who sketched and noted the initial on-site measurements is fully knowledgeable or even capable of reading or deciphering those same measurements back in the office to create the final measured drawings.        Third, there is a loss of accuracy due to translation between systems. The traditional process of creating measured drawings involves a lot of translation between systems, some being manual (pen and paper-based) while others being automated or computerized (like CAD applications). The initial measurements are typically taken by a surveyor or contractor. As used herein the terms surveyor, contractor, and operator are used to refer to any person recording data for use in creating measured drawings, or using said data to actually create the drawings.        
Sometimes more than one surveyor will work at a job-site and these surveyors may use different systems for taking measurements, and different notations, etc. At some point each note on every sketch must be translated to a data format that is compatible with the drawing system, be it man or machine. The individual measurements need to be collected and someone must manually translate the measurements into a cohesive, consistent format. Errors may often creep into the data at this point. The translation from sketch to CAD data is typically done by the CAD operator while creating the final CAD drawing. This is done according to his/her interpretation of the sketched drawing, one line at a time, which is again a potential source of error. When the sketch data does not translate to a perfect drawing, a skilled CAD operator will make adjustments, often according to their own subjectiveness to produce what appears to be the correct final drawing. Since so many individuals are involved, often using slightly different methods of interpretation, the traditional methods of creating measured drawings lack consistency, and it is not uncommon for two independent surveyors to create very different measured drawings for the exact same building.
There have been attempts to address the problems associated with the traditional measured drawings process. These include the PenMap application from Penmetrics, Inc. and the PlanSurveyor application from InfoQuest Technologies, Inc. Both of these systems utilize a computerized sketch pad and custom CAD software designed specifically to facilitate drawing of each element of a structure while walking the site. This approach does not provide a data acquisition procedure and requires the user to function as the data input/output, storage, KBS, and the draftsperson simultaneously. These systems replace the pencil and paper used in the traditional method, and as such are more convenient, but otherwise provide little other benefit. Other available systems incorporate automated measuring devices such as scanning lasers and photogrammetry, which are very sophisticated technology with limited application, are often difficult to use, and drive the cost of producing measured drawings upwards and beyond the reach of many potential consumers. What is needed is a system and a method that not only addresses the problems associated with the traditional method, namely the reliance on operator skill, the lack of relational linking between structural objects, and the loss of accuracy due to multiple translation between systems, but does so rapidly, conveniently, and at a cost that is desirable or accessible to the majority of consumers.